• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1000-1002
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• 2005

In the Bluetooth piconet in which up to 7 slave devices can be connected simultaneously at one network instance, the wireless data expected to be sent over to the RF interface should be sliced by the unit of 1 micrometer, which is a requirement in the specification of the Bluetooth version 1.1. In this contribution, we have designed a digital low-pass filter which is able to slice the unstable analog signal fed from the RF interface to the Baseband, by the uniform unit of 1 micrometer, and is also capable of removing the possible noise which can be caused by the analog circuit system. The low-pass filter operated well in the various modes of the Bluetooth RF embedded Baseband chip such as sleep mode, normal mode, and high-speed mode at 12MHz, 24MHz, and 48MHz respectively.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.69-76
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• 2012

This paper proposes an efficient power consumption scheme using sleep mode in home gateway. The scheme by this paper classifies incoming real time packet and non-real time packet in home gateway and delay non-real time packet. Therefore, the home gateway can have longer sleep time because non-real time packet can get additional delay time by proposing mechanism using timer. We use non-preemptive two priority queueing model for performance analysis. As a results, we verify that power consumption of proposed scheme is reduced more than existing scheme by delay of non-real time traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.37-41
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• 2018

In this paper, we evaluate the power consumption of IEEE802.15.4e TSCH which uses the specific link scheduling scheme proposed in reference[1]. And we also compares it with the power consumption of conventional single channel IEEE802.15.4. The power consumption of IEEE802.15.4e TSCH is smaller than the conventional one under the any conditions of traffic. The reasons can be explained as the followings. Firstly, TSCH does not have backoff time because of using the collision free link scheduling. Secondly, there is the timing difference of MAC offset parameter between TSCH and conventional IEEE802.15.4 Lastly, the devices in TSCH mode sleep during the time slots which are not assigned to itself.

• Convergence Security Journal
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• v.13 no.4
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• pp.27-32
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• 2013

In this paper, technologies applied to design urination detection device on diaper that issues an alarm signal to guardian within 10~20m are introduced. It features power saving that uses both low power bluetooth v4.0 chip and low-power program scheme that makes sensor and mirco-controller to be sleep mode while data is not receiving from sensor. Urination detection algorithm that utilizes the difference between previous sensing data and current values is used to improve the degree of the detection precision level. The device designed with the suggested technologies shows the performance that is 100ml of the minimum urine amount for detection, more than 90% of urination detection degree, and 100% of wireless communication success rate.

• Journal of Information Display
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• v.7 no.3
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• pp.5-8
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• 2006

A novel a-Si TFT integrated gate driver circuit using multi-thread driving has been developed. The circuit consists of two independent shift registers alternating between the two modes, "wake" and "sleep". The degradation of the circuit is retarded because the bias stress is removed during the sleep mode. It has been successfully integrated in 14.1-in. XGA LCD Panel, showing enhanced stability.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.175-178
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• 2011

서버 클러스터는 성능을 보장하기 위하여, 요청 수에 상관없이 미리 측정된 최대 부하 시점에서 처리 가능한 서버 수를 항상 운영하고 있다. 이것은 서비스의 품질은 보장할 수 있으나, 소비 전력 효율이 낮아 상당한 전력을 낭비하는 단점이 있다. 본 논문에서는 사용자 요청 수에 기반하여 동작시킬 서버의 수를 결정하는 알고리즘을 제안한다. 제안된 방식은 기존에 학습된 정보(과거 정보)와 현재의 정보에 근거하여 Off/Sleep 상태의 서버를 On 시키거나, On 상태의 서버를 Off/Sleep시켜, 현 시점에서 필요한 최적의 서버대수를 유지하도록 했다. 15대의 서버로 클러스터를 구성하고, SPECweb을 통해 실험을 수행하였다. 실험결과, 서버 모드를 제어할 경우에 제어하지 않는 경우에 비해 약 35%의 전력이 절감되고, 본 논문에서 제안하는 학습 방법을 추가로 적용할 경우 약 5%의 전력이 추가로 절감되었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.731-736
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• 2017

In this paper, we propose a simplified tag collection algorithm to improve the performances of ISO/IEC 18000-7, which is a standard for an active RFID system. The proposed algorithm modifies the collection command that enables to start a tag collection round. The modified collection command includes the results of the listen period response for the previous collection round. Tags that receive the collection command check the collision status for their responses. If there is no collision, tags transmit their additional data and go into the sleep mode without the point-to-point read command and sleep command. A collection round for the standard consists of a collection command and response, a read command and response, and sleep command. On the other hand, in the proposed algorithm, a collection round consists of a collection command and response. The simulation results showed that the proposed algorithm can improve the identification delay about 16% compared with the standard when the number of tags are 300.

• Journal of IKEEE
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• v.22 no.3
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• pp.842-845
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• 2018

In this paper, we propose low-power operational methods for thermal-energy-harvesting sensor circuits. Here, the amount of harvested current has been measured as low as 8uA. However the DC power consumption of the sensor circuit is known to consume much larger than 8uA. Thus, We propose the hardware-based power gating and software-based active/sleep timing control schemes, respectively, for controlling the power consumption of sensor circuit. In the hardware-based power gating scheme, if the ratio of Toff/Ton is larger than 22, the sensor can consume less than 8uA. For the software-based active/sleep control scheme, if the ratio of Tslp/Tact is larger than 3, we can suppress the current consumption below 8uA. The hardware-based and software-based schemes proposed in this paper would be helpful in various applications of energy-harvesting sensor circuits, where the power consumption is limited by an amount of harvested energy.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.3
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• pp.371-379
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• 1999

본 연구에서는 기존의 IS-95B에서 IMT 2000으로의 자연스러운 진화를 지원하면서, IMT2000을 효과적으로 지원하기 위하여 CDMA 기반한 패켓데이타 서비스용 MAC 프로토콜을 설계하고 성능을 평가한다. 제안한 방안은 기본적으로 비연결형 패켓 전송 방식을 지원하여 채널의 재사용률을 높히고, 트래픽의 전송시에만 채널을 사용하는 DTX(Dis-continous Transmission Mode)에 기반하므로 채널 자원의 효율을 극대화 한다. 아울러 트래픽의 전송시 5ms에 기반한 전용제어 채널관리 기능을 제공하므로서 빠른 채널 제어를 지원한다. 또한 Sleep-mode에 기반한 전용 제어 채널 제어 기능을 제공하여 단말의 전력 감소를 최소화한다. 아울러, 상태 천이에 따라서 패켓의 송수신이 없는 경우에는 네트워크내의 데이터베이스 정보 관리 부하를 극소화 하는 방안을 제공한다. 특히, 본 논문에서 제안한 방안은 현재 cdmaOne 의 표준으로서 TR 45.5의 승인을 받아 ITU-R의 IMT2000 RTT(Radio Transmission Technology)로서 제출되어 있는 상태이다.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.1-5
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• 2012

This paper describes a 150-Mb/s monolithic optical receiver for plastic optical fiber link using a standard CMOS technology. The receiver integrates a photodiode using an N-well/P-substrate junction, a pre amplifier, a post amplifier, and an output driver. The size, PN-junction type, and the number of metal fingers of the photodiode are optimized to meet the link requirements. The N-well/P-substrate photodiode has a 200-${\mu}m$ by 200-${\mu}m$ optical window, 0.1-A/W responsivity, 7.6-pF junction capacitance and 113-MHz bandwidth. The monolithic receiver can successfully convert 150-Mb/s optical signal into digital data through up to 30-m plastic optical fiber link with -10.4 dBm of optical sensitivity. The receiver occupies 0.56-$mm^2$ area including electrostatic discharge protection diodes and bonding pads. To reduce unnecessary power consumption when the light is not over threshold or not modulating, a simple light detector and a signal detector are introduced. In active mode, the receiver core consumes 5.8-mA DC currents at 150-Mb/s data rate from a single 3.3 V supply, while consumes only $120{\mu}W$ in the sleep mode.